1. Field of the Invention
This invention relates generally to electronic assemblies, and, more particularly, to arrangements for cooling arrays of electronic circuit boards.
2. Description of Related Art
Electronic assemblies are commonly manufactured in the form of circuit boards that plug into a backplane. Numerous electronic components are attached to each circuit board and are connected together via conductive traces or wires. Each circuit board generally has one or more connectors at one end, which are designed to mate with respective connector(s) on the backplane. Different circuit boards can be plugged into different standard locations, or “slots,” of the backplane, substantially in parallel. The backplane generally includes traces or wires for establishing connections between the different circuit boards that plug into the backplane.
The circuit boards and the backplane are generally housed together within an enclosure called a “card cage” or “chassis.” The chassis generally also houses power supplies for energizing the circuit boards and air movers such as fans or blowers for cooling the circuit boards. The chassis also typically includes card guides, which form channels within which circuit boards can slide to ensure that they are inserted into backplane connectors with proper spacing and alignment.
Electronic systems are being developed that provide orthogonal arrays of circuit boards. Each array includes circuit boards oriented in parallel; however, the different arrays are orthogonal to each other. An example of this type of system is disclosed in U.S. patent application Ser. No. 10/954,865, entitled, “Electronic System with Non-Parallel Arrays of Circuit Board Assemblies,” which is hereby incorporated by reference.
With orthogonal arrays of circuit boards, one array may dissipate relatively little power and may be air cooled, whereas another array may dissipate relatively higher power and may be liquid cooled.
We have recognized that, where possible, it is strongly preferred for both arrays of circuit boards to be air cooled. Air cooling is preferred because it reduces cost and complexity as compared with liquid cooling. What is desired, therefore, is an effective way of air cooling orthogonal arrays of circuit boards.